Portal de Periódicos da CAPES

Nesting biology of the yellowjacket, Vespula flavopilosa (Hymenoptera: Vespidae).

1980; Kansas (Central States) Entomological Society; Volume: 53; Issue: 2 Linguagem: Inglês

1937-2353

John F. MacDonald, Robert W. Matthews, Robert S. Jacobson,

Insect and Pesticide Research

Colonies of a recently described yellowjacket species, Vespula flavopilosa Jacobson, typically possess a shorter seasonal cycle and are significantly smaller than concurrently col lected colonies of the broadly sympatric eastern yellowjacket, V. maculifrons (Buysson). Typical V. flavopilosa colonies were sub terranean, completed their seasonal cycle by early October, pos sessed peak worker populations of 800 to 1400, and constructed nests of 2000 to 5000 cells, of which 15 to 20% reared queens. Spring V. flavopilosa queens occasionally usurped incipient V. maculifrons and V. vulgaris (L.) colonies, and V. flavopilosa can be a host for V. squamosa (Drury). The yellowjackets of North America can be divided into two species groups, V. rufa (L.) and V. vulgaris (L.), on the basis of morphology and behavior (MacDonald et al., 1976). Vespula flavopilosa Jacobson is a re cently described member of the latter group (Jacobson et al., 1978). This paper presents the first detailed account of its nesting biology, including a comparison of V. flavopilosa biology with that of other V. vulgaris group members, particularly the closely related broadly sympatric eastern yel lowjacket, V. maculifrons (Buysson). As nests of V. flavopilosa and V. maculifrons are superficially quite similar, we contrast nest structure and seasonal cycles, showing that the two species consistently differ in certain biological attributes in addition to the morphological traits examined by Jacobson et al. (1978). Study Sites and Methods Colonies of southeastern yellowjacket species located by systematic search and reported by interested persons were destructively sampled throughout the 1974 nesting season; follow-up samples were made in 1975 and 1977. Most colonies were collected around 3 research facilities in heavi ly forested mountainous areas (elev. 760-1500 m) of western North Caro 1 Current address: Department of Entomology, Purdue University, West Lafayette, Indiana, 47907. 2 Associate Professor and Research Assistant respectively. Supported in part by the National Science Foundation (DEB 75-21442). Received for publication 4 July 1979. This content downloaded from 157.55.39.64 on Fri, 22 Jul 2016 05:26:53 UTC All use subject to http://about.jstor.org/terms VOLUME 53, NUMBER 2 449 lina: the Coweeta Hydrologie lab; Highlands Biological Station; and West ern Carolina University, Cullowhee. Fewer colonies were collected just south of the above sites near Clayton, Georgia, and around Athens, Georgia, 145 km to the south (elev. 225 m). All located and reported colonies were confirmed as to species, but in opportune location (cemeteries, rock walls, some gardens, etc.) made ex cavation of many nests infeasible; thus, our analyzed sample is less than the total number of colonies found. Unless otherwise indicated, colonies were destroyed with carbon disulfide after dark when nearly every adult was present. The following morning nests were excavated with care taken to collect all adult yellowjackets and colony associates. Collected nests were frozen or freeze dried for later analysis. Results and Discussion distribution and abundance: Vespula flavopilosa comprised nearly 40% of the total colonies located in western North Carolina and northeastern Georgia, but was relatively uncommon around Athens, Georgia (Table 1) and notably absent south of Athens and in north-central Georgia. Vespula maculifrons was the most abundant yellowjacket in all the above locations. Based on 33 colonies encountered over 3 years of study, V. flavopilosa appears to nest primarily in open disturbed habitats adjacent to hardwood forests. Pooling all our V. flavopilosa nest collections and grouping them according to habitat provided the following distribution: undisturbed wood land?6; roadbanks?11; lawns and gardens?10; pastures and clearings? 6. However, half of these colonies were located through referrals and, con sequently, our sample is likely biased toward areas of human activity. Occasionally, Vespula colonies may exhibit a clumped distribution (Spradbery, 1973). However, nearly all V. flavopilosa colonies were widely separated even in the most productive habitats. In a notable exception, 4 V. flavopilosa and 2 V. maculifrons colonies were found on Sep. 10, 1974 within a 50 m radius in lawns and gardens of a residential area of Cullowhee, North Carolina. Interestingly, the mean number of worker cells of the 4 V. flavopilosa nests (x = 1804) closely approximated that for all V. flavopilosa nests (x = 1871), but the mean number of worker cells in the 2 V. maculi frons nests (x = 3292) was about half that for all V. maculifrons nests (x = 6211) (see Table 1). Because of large variability in nest size among concur rently collected Vespula nests and the small sample size any conclusions must be guarded, but it appears colony clumping interfered with develop ment of the 2 V. maculifrons colonies. nest location and architecture: Selected measurable nest char acteristics are summarized in Table 2. All 33 V. flavopilosa nests were sub terranean, each apparently initiated by a queen in a small diameter under ground cavity such as a rodent burrow tunnel or decayed root passage; all This content downloaded from 157.55.39.64 on Fri, 22 Jul 2016 05:26:53 UTC All use subject to http://about.jstor.org/terms Table 1. Comparison of worker cell counts from mature nests of V. flavopilosa and V. maculifrons.8 V. flavopilosa V. maculifrons Locality Nests Range Median Nests Range O c z > r o