How Much Does a Wasp Weigh in Grams?
WouterUsing a Mitutoyo Absolute Digimatic Caliper, wasps were measured to calculate their head width. Head width is a measure of body size and is correlated with body weight in studied sphecoid wasps. It is estimated that the head width of the female Cerceris fumipennis is an appropriate measure of body size.
In this study, wasps were collected from eight sites. The data were analyzed using analysis of variance in SYSTAT v.13.1 (Systat Software Inc., Chicago, IL, USA). Using Tukey’s test, post-hoc comparisons between sites were performed.
There was a significant difference in the average wet weight between small and large wasps. The average wet weight of large wasps was 116 +- 46.1 mg, compared to 29.7 +- 24.8 mg for small wasps. This result indicated that large wasps captured more total beetles.
Agrilus and Buprestis were the two prey types collected by small and large wasps, respectively. Beetles collected by large wasps had an average wet weight of 116 +- 46.1 mg, while those collected by small wasps had an average wet weight 29.7 +- 24.8 mg.
Prey load is defined as prey weight/predicted wasp weight x 100. Using this formula, it was determined that the smallest prey load was 4.8% of the wasp’s weight. On the other hand, the largest prey load was 150.2% of the wasp’s weight. The prey load was not significantly different among sites.
In the Tasman region of New Zealand, the average number of wasp nests per hectare is 40. These nests grow to about 1.8 metres in diameter and can contain thousands of wasps. This is important because these wasps are a great threat to the forestry industry and other industries.
