Life History, Development, and Rearing ofEucryptorrhynchus brandti(Coleoptera: Curculionidae) in Quarantine

Abstract

Eucryptorrhynchus hrandti (Harold) (Coleóptera; Curculionidae) was identified in China and studied in quarantine in tbe United States as a potential biological control agent for the invasive weed, tree of heaven, Ailanthus altissima (Mill.) Swingle (Sapindales: Simaroubaceae). Studies on its general biology and development, and the most efficacious rearing method were conducted. E. brandti is univoltine. The metathoracic sternite and first abdominal segment are convex in females and concave or flat in males. Females are larger than males. Female and male sagittal measurements averaged 11.50 ± 0.14 (± SEM) and 10.35 ± 0.09 mm, respectively. Transversal measurements averaged 4.22 ± 0.06 and 3.73 ± 0.05 mm for females and males, respectively. Mean weight of females and males were 0.10 ± 0.003 and 0.07 ± 0.002 g, respectively. Females lived longer than males, averaging 66.3 ± 6.8 d and 46.5 ± 7.3 d, respectively. The egg stage averaged 5.0 ± 0.9 d, and the larval stage had six stadia and developed in 110 ± 15.0 d; the pupal stage was 16 ± 7.0 d at 25°C. A method for rearing E. brandti on cut A. altissima billets under quarantine conditions was developed. The most efficient egg-to-adult rearing method involved caging 12 males and 12 females or 24 males and 24 females for 7 d on 23-92-cm-long biUets. Duration up to 3 wk after cutting did not affect adult emergence. This information will facilitate laboratory rearing and conducting host specificity tests to determine agent impact on nontarget species.

Occurrence and development ofEucryptorrhynchus brandtiandE. chinensis(Coleoptera: Curculionidae) onAilanthus altissimatrees subjected to different levels of mechanical damage

“…adults have similar black and white colours. However, E. brandti is shorter in length (10-12 mm) than E. chinensis (15-18 mm) (Herrick, Salom, Kok, & McAvoy, 2011). Eucryptorrhynchus chinensis also has red markings not found on E. brandti.…”

“…Larval sampling (bark section removal) began in June, one month after the high and extreme mechanical injury trees were treated. All larvae found were collected in ethyl alcohol for measurement of the head capsule width and body length for designation to instar (L1-L6) (Herrick et al, 2011). The number of adult emergence holes and their height above ground in intervals of one metre and tree health were recorded every month or two from May to November.…”

“…Adults were occasionally seen mating on the tree trunks, but no obvious feeding on the bark was evident. However, in rearing E. brandti at the Virginia Tech quarantine facility, adults were caged on A. altissima logs (Herrick et al, 2011); when the bark from these logs was removed and held up to a light, small 1-2 mm holes were visible. These holes indicated that adult feeding on the bark occurs but only in the white/greenish furrows on the outer surface of the bark.…”

“…Eucryptorrhynchus brandti is being considered as a candidate for biological control in the USA and was found to be highly host specific to A. altissima (Herrick, McAvoy, Snyder, Salom, & Kok, 2012). A successful rearing method was developed by Herrick, Salom, Kok, and McAvoy (2011). Based on the reports from China discussed above, E. brandti and E. chinensis are reported to be capable of causing death or decline of A. altissima.…”

Mass Rearing of the Stem-Galling Wasp Tetramesa romana, a Biological Control Agent of the Invasive Weed Arundo donax

“…Smallscale quarantine laboratory rearing is required to determine life cycles of candidate agents and perform host range and efficacy studies (e.g. Price et al, 2003;Martin et al, 2004;Herrick et al, 2011). However, only rarely are attempts made to mass rear insects for weed control, as human-aided or natural agent dispersal among field sites is the predominant approach (Van Driesche et al, 2002.…”