Biological traits and field distribution of introduced Arhopalus species in Central Argentina

Abstract

Arhopalus rusticus rusticus and Arhopalus syriacus (Coleoptera: Cerambycidae) are exotic forestry pests that coexist in Córdoba (Argentina). To contribute to forest management strategies, we examined how their emergence, development, and abundance affect the sex ratio. We found a dispersal sex ratio of 0.5:0.5 (males:females) in both species. The birth sex ratio was 0.5:0.5 in A. syriacus and 0.6:0.4 in A. r. rusticus. In rearing experiments, A. r. rusticus had larger individuals, with several larval instars and high survival ratio, but developmental time was shorter in A. syriacus. We found an asymmetric distribution, but there are indications that the range of A. syriacus is advancing northward.

Keywords:

• Developmental time
• survival
• abundance
• sex ratio
• forestry pests
• Cerambycidae

Disclosure statement

The authors declare that they have no conflict of interest.

Notes

1 A semi-synthetic artificial diet modified from Iglesias et al. (1989) (ingredients for almost 1.5 kg of diet: 600 ml water, 56 g agar, 8 g nipagin, 4 g benzoic acid, 250 g pine sawdust, 44 g yeast, 88 g corn flour, 176 g wheat germ, 30 g glucose, 48 g casein, 30 g sucrose, 4 g ascorbic acid and 2 tablets of Supradyn vitamins), was used for rearing A. syriacus and A. r. rusticus. Diet was poured into trays while still hot and stored at 15 °C in the refrigerator. On the days of food replacement, the diet was taken out 2 hours earlier to reach room temperature before use (Keena and Moore 2010).