Protection of the earthís biological diversity has emerged as a major priority for the natural sciences and public policy. The first step in achievement of this goal is assessment: How many species live in an area, and what are their identities? Without this fundamental information, the study of species interactions, the monitoring of diversity over time, and the use of these data in policy decisions, is impossible. As the biodiversity of virtually all regions remains poorly documented, the completion of local species inventories remains an ongoing task and a valuable contribution. Biodiversity research is no longer limited to ìwilderness areasî but includes increasing attention to urban settings. Urban agglomerations have dramatically increased over the past century; today, 47% of the worldís population lives in urban areas, and this is expected to increase to 60% by 2030. Thus, urban biodiversity investigations are relevant to society, and such studies play an important role in urban planning. Indeed, these data bear on such issues as park design, groundwater management, solid waste disposal, public health and pest management. In northeastern New Jersey, where undisturbed areas are scarce and development ceaseless, the documentation of biodiversity requires immediate attention. The arthropods (insects, spiders, crabs, etc.) are likely the largest group of animals on earth (up to 10 million species). Within this group, the insect order Hymenoptera (wasps, ants, bees, sawflies) is a valuable focus for biodiversity surveys. This is one of the largest insect orders: over 100,000 species have been discovered, and the actual number may exceed 500,000. Through both detrimental (e. g., timber destruction) and beneficial (e. g., pollination) pathways, the activity of these insects has profound effects on the global economy. Many hymenopterans are ìkeystoneî species whose removal affects the status of other species in the community; therefore, their diversity affects the overall ìhealthî of an ecosystem. Ironically, hymenopterans are themselves very sensitive to environmental conditions and are often negatively impacted by habitat degradation.
Since 2000, the Codella lab has investigated the effects of human activity on hymenopteran biodiversity at Watchung Reservation. Watchung is a 2000-acre preserve in Union County. It encompasses land of great historical significance. As is typical of northeastern forests, Watchungís woodlands are highly disturbed, and evidence of both Native American quarrying and European farming is scattered throughout. Indeed, human activity, over the course of many centuries, has left its mark on Watchungís landscape and ecological communities. Today, the Reservation is a heterogeneous ìgreen islandî amidst a densely populated region, and its diverse array of habitats offers many recreational attractions to the surrounding municipalities. Thus, many land management decisions within the park are made with these uses in mind. In addition, Watchung is in close contact with Interstate 78. In 1986, after years of controversy, the Federal Highway Administration completed I-78 by routing 3.5 miles through the northern edge of the Reservation. Despite its ìenvironmentally enlightenedî design, which minimizes the visual impact of the road and provides corridor bridges for wildlife, the presence of I-78 could have a potentially major impact on biodiversity. Finally, specific human responses to natural events, such as pest insect outbreaks, can have long-lasting effects on the population dynamics within ecological communities. So there are a multitude of avenues through which human behavior can influence the trajectory of Watchung Reservationís biodiversity. Our sampling has focused on Watchingís coniferous (pine, spruce, etc.) forests. These habitats generally show high hymenopteran diversity and are situated so as to allow comparison of species richness at various levels of human impact. To date, we have collected approximately 1800 specimens (about 700 have been formally identified) representing 120 species in 25 families.
From May through October, we maintain yellow and blue pan traps in the collection sites (see map). We also collect throughout the area using various manual methods. Traps are serviced three times weekly (traps are water- rather than alcohol-filled to avoid injury to wildlife and stray animals). We collect samples in 70% ethanol and transport them to the lab, where we sort specimens to the superfamily level. Specimens are then preserved using professional museum methods (either on pins or in permanent ethanol vials, depending on the specimen). Over time, specimens are identified to family and morphospecies (and eventually, to genus and species), uniquely numbered, cataloged in a computer database, and photographed.
A list of Watchung Reservation collection locations:
Boy Scout Camp Pine Preservation PH-L grid PH-R grid PO-P grid PO-S grid PR-S grid PR-W grid
The following is a shortened taxonomic classification of the Order Hymenoptera in accordance with what was collected in the field and identified in the lab.
Superfamily ApoideaSeries Apiformes Family Halictidae Family Megachilidae Series Spheciformes Family Sphecidae
Superfamily CeraphronoideaFamily Megaspilidae
Superfamily ChrysidoideaFamily Chrysididae
Superfamily Chalcidoidea
Superfamily Cynipoidea
Superfamily Evanioidea
Superfamily IchneumonoideaFamily Ichneumonidae Family Braconidae
Superfamily PlatygastroideaFamily Scelionidae
Superfamily ProctrupoideaFamily Diapriidae Family Proctrupoidae
Superfamily VespoideaFamily Formicidae Family Mutillidae Family Pompilidae Family Vespidae
SUBORDER SYMPHYTA (horntails, sawflies) Superfamily Tenthredinoidea
Family Tenthredinidae
Superfamily MegalodontoideaFamily Pamphiliidae
Superfamily XyeloideaFamily Xiphydriidae
Unknown Symphyta