On behalf of the Pacific Science Association, I wish to welcome everyone to this workshop. The PSA is an international, non-governmental, regional scientific organization founded in Hawaii in 1920. It is thus 70 years old this year. 

(This is the first paragrah. There is no abstract.)

Abstract-Nearly all pest arthropods now present in Hawaii are nonnative species that have been introduced to the island since their discovery by man ca. 1,000 years ago. A few introduced pests, such as houseflies, head and pubic lice, and cockroaches, were present at the time of European discovery (mid to late 18th century), presumably as a result of Polynesian exploration and trade. Accidental introductions of pest arthropods became more common during the 19th century as a result of commerce with the outside world, and this trend has accelerated during the 20th century, despite the application of quarantine regulations during the 1890s. The advent of regular trans-Pacific air travel during the 1940s and of jet aircraft during the 1960s have provided new opportunities for rapid dispersal of pest arthropods, to Hawaii and throughout the Pacific Basin. These are exemplified by recent epidemic outbreaks of such new pests as the spiraling whitefly, the leucaena psyllid and the melon thrips. Due to the constantly increasing volume of transPacific air traffic to Hawaii, and to the existence there of many underutilized ecological niches, it appears likely that new pests will continue to become established there at a relatively high rate, despite improvements in quarantine enforcement and pest detection techniques. 

The introduction of exotic species into Guam is a continuing problem, with the many serious insect pests being post World War II introductions. In the 1980s at least 25 new species were accidentally introduced. New pests include a grasshopper, a scarab beetle, several noctuid moths and a variety of small beetles, scales, thrips, whiteflies. In the last decade about one-third of the new pests on Guam apparently originated from the New World via Hawaii. Other pests arrived from the Oriental region and from other islands in the Micronesian area. Although the mode of introduction of most insects cannot be deter­mined with precision, it can be deduced in at least three recent cases, one having arrived via an Air Force flight, and two having arrived with commercial shipments of ornamentals from Hawaii. The movement of ornamental plants and flowers is probably the most important means by which insects are currently moved around the Pacific region.

In 1986, surveys of crop insects were conducted in Palau, Yap, Chuuk, Pohnpei, Kosrae, and in 1989, in Jaluit and Majuro. In the Marshalls, 20 species of insects were found to have entered Majuro or Jaluit for the first time. Of these, ten species were new to the Marshalls, and the rest were already present on other atolls. Using 1975 as the base year, Majuro acquired 16 new records, corresponding to a rate of 1.1 new pests per year, and Jaluit had nine new records, or 0.6 new insects per year. These rates are lower than those for Guam, which got 2.5 new introductions per year during the 1980s. In the Carolines, between 1976 and 1986, Pohnpei acquired about 1.4 new insects per year, Yap 1.1, Palau 0. 7, Kosrae 0. 7, and Chuuk 0.6. Many of the new records in the Carolines were range extensions of insects already present. In both the Carolines and the Marshalls, scales, whiteflies, and other Homoptera accounted for most of the new introductions, but new species of moths, beetles, flies, and thrips were represented as well. 

Over 50 new reports of plant diseases were included in the Guam Agricultural Experiment Station Annual report of 1988. Some have evidently been here for some time  but  have escaped detection previously; others are recent introductions. Bacterial blight of cassava (Xanthomonas campestris pv. manihotis) was  first detected in  1986. Fruit blotch of watermelon (Pseudomonas pseudoalcaligenes subsp. ci­trulli) was first seen in 1987; several damaging blotch epidemics have resulted in serious economic losses to watermelon growers. A sample of a lanzones tree (Lansium domesticum) with stem galls was found to have plant parasitic nematodes. Leaf scald of cabbage was  found in 1988; it is caused by a strain of Xanthomonas campestris pv. campestris, the same bacterium causing black rot. More recently, Bacterial leaf blight (Pseudomonas avenae) and  leaf blight (Bipolaris maydis) have been found on com. Some control measures are suggested that can slow the rate of pest importation. 

The major vector borne diseases relate to infections with ma­larial, filarial and arboviral pathogens. Within recent decades the actual or potential movement of these pathogens and/or their vectors into or within the Pacific Region has concerned national and international health authorities. The introduction of  vectors of malaria into areas where they do not exist is a major concern; the appearance of exotic Anopheles species and instances of local malaria transmission in Guam illustrate this concern, and islands of the southwest Pacific remain vulnerable. Dengue fever has been active in recent years and, although some indigenous mosquitoes are vectors, further dispersal of the efficient exotic vectors Aedes aegypti and Ae. albopictus in the region should be prevented because of their domestic habits. Other arboviruses also con­stitute a threat; the introduction of Ross River virus 10 years ago was an instance where local mosquitoes were competent vectors of an exotic pathogen. Filarisasis is not considered an acute problem but efficient Aedes vectors (which may also be  arbovirus vectors) should not be allowed to spread to areas with less competent indigenous filarial vectors. Vector control can be difficult once exotic pests are established; quarantine provisions, and efficient routine surveillance and control operations can be used to help prevent many of the above concerns. 

Introduced ornamental plants that are considered weeds on Guam include Antigonon leptopus Hooker & Amott, Spathodea cam­panulata Beauv., Coccinea grandis, Bauhinia monandra Kurz., Clero­dendrum quadriloculare (Blanco) Merrill, Lantana camara L., Ficus spp., Asystasia gangetica (L.), Pilea microphylla (L.) Liebm., Wedelia trilobata (L.) Hitche., Mikania scandens and Mimosa pudica L. Char­acteristics of ornamental plants that could become weeds on Guam include rapid growth/regrowth and prolific seed production.

Pomacea canaliculata (Lamarck) was introduced as a human food from Argentina into Taiwan (China) in 1979-80. It was introduced from Taiwan to Japan in 1981, the Philippines in 1982, China (Guang­dong, Fuzhou, & Hangzhou) in March 1985, Korea (Suwon) in 1987 or earlier, Malaysia (Sarawak) in 1987 or earlier, and Indonesia and Thai­land by 1989. The snail has escaped from aquaculture and established in open fields affecting aquatic plants. Estimation of areas infested by this snail was 171,425 ha in Taiwan in 1986, 16,195 ha in Japan in 1989, and ca. 400,000 ha in the Philippines in 1989. In Japan ethylthimetone + thiocyclam G, cartap G, bensultap G, and IBP G are registered as snail repellents, and IBP G shows some toxicity. Calcium cyanamide is registered as a fertilizer with toxicity to snails. Metalde­hyde, triphenyl-tin acetate, and niclosamide are not registered for con­trol purposes because of high toxicity to fish. In Taiwan, however, me­taldehyde and triphenyl-tin acetate are registered. In addition, the predatory black carp (Mylopharyngodon piceus (Richardson)) and common carp (Cyprinus carpio L.) are recommended as control agents. In the Philippines, 5  chemicals including triphenyl tin-acetate, niclosam­ide, and endosulfan are in the market. Hand-picking, ducks, setting of metal screens, etc. are also recommended. More effective methods of control have yet to be developed. 

Boiga irregularis was probably introduced on Guam a little over forty years ago. Since then, the snake population has become very dense and has been responsible for enormous biological, economic, and cultural damages. Because of severe reductions in vertebrate biodivers­ity,  changes in  insect densities and diversity and vegetational shifts should occur.

Lantana camara L.  was introduced into Micronesia as an ornamental plant at the tum of the century and quickly established as a significant weed pest throughout the region. Over the past forty years various natural enemies of lantana have been introduced into Micro­nesia in an attempt to curb the spread of the lantana. However, little information has come out of the area with respect to the establishment and effectiveness of these species. For this reason, surveys were under­taken to assess the status and natural insect enemies oflantana on major islands within the Caroline and Mariana island groups. Lantana was found to be widespread throughout the region although its abundance and pest status varied between islands. At  least four different color varieties were noted, the most common of which resembled the Ha­waiian Pink, L. camara var. aculeata. Seven of the thirteen exotic insect species introduced into the area were found to  have established, al­though not all  were found on  all islands where lantana was present. Similarly, certain insects were more effective bio-control agents than others although once again inter-island variability was evident. The five most important insect species, in terms of their distribution and effec­tiveness, were the tingid bug, Teleonemia scrupulosa Stal; the hispine beetle, Uroplata girardi Pie; the pterophorid moth, Lantanophaga pus­illidactyla (Walker); the tortricid moth, Epinotia lantana (Busck), and the pod-fly Ophiomyia lantanae (Froggat). 

Australia and Oceanic Pacific countries share a number of major introduced insect and weed pests and both must endure contin­uing intrusion of new pests. Some important Pacific pests have already been brought under biological control in Australia and the natural ene­mies employed will almost certainly be of value also in the Pacific. Conversely, some pests  already in the  Pacific, but which have  not reached Australia (e.g. banana skipper, spiraling whitefly), are targets for biological control programs. If these programs are successful (as they probably will be), the reduction in pest densities should help to delay the further spread of these pests. An additional important benefit is that, if other countries are invaded, tested natural enemies will be readily available. There are clearly mutual advantages in close regional collaboration in biological control activities. Reasons for emphasizing the biological control approach and criteria for selection of target pests are discussed. 

Banana skipper,  Erionota thrax (L.) (Lepidop­tera:Hesperiidae) a butterfly of Southeast Asian origin, was first recorded in Papua New Guinea in  1983. Since 1987, it has spread throughout the mainland from sea level to 2500 m. The larvae feed on all species of bananas reducing fruit yields and preventing the traditional use of leaves for other purposes. No hosts other than Musaceae were recorded for E. thrax in Papua New Guinea. A joint survey by CSIRO and the Papua New Guinea Department of Agriculture & Livestock investigated the natural enemies and abundance of  E.  thrax as  a  preliminary to biological control of the pest in Papua New Guinea. Of three egg par­asitoids found attacking E.  thrax, only Ooencyrtus erionotae Ferriere significantly influenced its abundance. Natural enemies of larvae and pupae were uncommon and an important larval parasitoid of E. thrax in Southeast Asia, Apanteles erionotae Wilkinson, was absent. E.  thrax could spread from Papua New Guinea, posing a threat to  bananas throughout the south Pacific region.

Chromolaena odorata (L.) King and Robinson is a neotrop­ical weed, spread all over the humid tropical regions of Asia, Africa and Micronesia. This paper reviews mechanical, cultural, chemical and biological control methods against this weed. Of these methods, biological control either alone or in combination with others seems to be the most promising one to  suppress this weed. 

The introduced breadfruit mealybug, Icerya aegyptiaca is a major pest in Kiribati and some other Micronesian atolls. It has been brought under effective biological control in the high islands of Micronesia by the introduction of a predatory ladybird beetle, Rodolia pumila. Like most other ladybirds, this species searches effectively at high prey densities, but inefficiently at low densities. When introduced to the rel­atively restricted atoll environment it soon reduces I. aegyptiaca pop­ulations to low levels. It then dies out, apparently being unable to find prey, whereupon there is an upsurge in mealybug populations. One control strategy would be to re-introduce R. pumila whenever mealybug populations reach a pre-determined action level. However, and preferably, other natural enemies could be introduced that might co-exist at low scale densities. In particular, the parasitic fly, Crypto­chetum grandicorne, may have appropriate characteristics. 

In December 1989, a Rapid Rural Appraisal (RRA) of taro agriculture was held in American Samoa. A survey of 32 farmers re­vealed several traditional methods of insect, disease and weed control. Planting Coleus blumei Beuth in or around a plantation was alleged to control the cluster caterpillar (Spodoptera litura (Fabricius)) and the taro planthopper (Tarophagus proserpina (Kirkaldy)). "Smoking" a field with a torch of coconut fronds 3 times a week reportedly controlled the planthopper. Allowing chickens to roam taro fields in search of cluster caterpillars for food, and leaving a cluster caterpillar-infested field fallow for 3 to 5  months supposedly suppressed cluster caterpillar numbers. Control of weeds was accomplished by mulching with coconut fronds and banana leaves. Using the shade of papaya and banana trees and growing taro in high density or in an intercropped scheme were also identified as weed control measures. Pulled and slashed weeds are fre­quently used as mulch, and the mat of mulch is periodically turned over to break up any rooted weeds. Paragrass was cited as a "fertilizer" weed and "mile-a-minute" (Mikania micrantha Kunth) was regarded as  a helpful plant. Herbicides promoted the growth of a different, more per­sistent weed population which was more difficult to control. Taro corm rot was controlled by selecting disease-free planting material, replanting in fallowed areas, and avoiding areas near Hibiscus tiliaceus L. trees. 

Insect wingbeat frequency has been used as a taxonomic character. To test the feasibility of developing instrumentation which monitors the identity and population density of flying insects, wingbeat frequencies of the mosquitoes, Aedes aegypti (L.) and A. triseriatus Say, were recorded using a microcomputer-based instrument which measured light reflected off the wings of individuals in flight. The wingbeat frequency and other spectral components from 403 individual recordings were used to train an artificial neural network. The trained network correctly identified the species and sex of mosquitoes in an independently recorded group of 57 mosquitoes. This technology has potential use for detecting and monitoring a wide range of flying insects.