Proactive classical biological control of Lycorma delicatula (Hemiptera: Fulgoridae) in California (U.S.): Host range testing of Anastatus orientalis (Hymenoptera: Eupelmidae)

Abstract

Lycorma delicatula (Hemiptera: Fulgoridae), the spotted lanternfly, native to China, invaded and established in the northeast U.S. in 2014. Since this time, populations have grown and spread rapidly, and invasion bridgeheads have been detected in mid-western states (i.e., Indiana in 2021). This invasive pest presents a significant threat to Californian agriculture. Therefore, a proactive classical biological control program using Anastatus orientalis (Hymenoptera: Eupelmidae), a L. delicatula egg parasitoid native to China, was initiated in anticipation of eventual establishment of L. delicatula in California. In support of this proactive approach, the potential host range of A. orientalis was investigated. Eggs of 34 insect species either native or non-native to the southwestern U.S. were assessed for suitability for parasitism and development of A. orientalis. Of the native species tested, 10, 13, and one were Hemiptera, Lepidoptera, and Mantodea, respectively. Of the non-native species, eight Hemiptera and two Lepidoptera were evaluated. Host range tests conducted in a quarantine facility, exposed individually mated A. orientalis females (Haplotype C) to non-target and target (i.e., L. delicatula) eggs in sequential no-choice and static choice experiments to determine suitability for parasitization and development. Additionally, the sex ratio, fertility, and size of offspring obtained from non-target and target eggs were evaluated. Results of host range testing indicated that A. orientalis is likely polyphagous and can successfully parasitize and develop in host species belonging to at least two different orders (i.e., Hemiptera, Lepidoptera) and seven families (Coreidae, Erebidae, Fulgoridae, Lasiocampidae, Pentatomidae, Saturniidae and Sphingidae). Prospects for use of A. orientalis as a classical biological control agent of L. delicatula in the southwestern U.S. are discussed.

Assessing the host range of Anastatus orientalis, an egg parasitoid of spotted lanternfly (Lycorma delicatula) using Eastern U.S. non-target species

“…We did not find any notable differences in the number of developing wasps that did not successfully emerge from the egg masses and the rate of this occurrence was very similar in the nontargets as it was for the controls. While H. halys was previously found to not be parasitized by A. orientalis (15), our tests and those of our colleagues (21) found that it could be parasitized. Also, Seo et al (15) found that the saturniid Antheraea pernyi was only parasitized if the eggs were immature and dissected out of a gravid female.…”

“…Additional host range testing will be conducted with the additional genetic lines we have in colony. However, this study, along with the work of Goḿez Marco et al (21), shows that A. orientalis Haplotype C is willing and able to develop in various non-target species but prefers to parasitize L. delicatula.…”

“…United States, was conducted by collaborators at the University of California Riverside (21). Together these studies show that A. orientalis Haplotype C prefers to parasitize L. delicatula egg masses but is willing to attack and is physiologically able to develop in various non-target species suggesting that it is facultatively oligophagous or polyphagous.…”

“…This manuscript describes testing of species of concern present in the eastern United States where L. delicatula currently is invasive. Due to concern about the threat of invasion by L. delicatula to the western United States, simultaneous coordinated testing of species resident to the western coast of the United States was conducted at the University of California Riverside Insectary and Quarantine Facility ( 21 ). To evaluate the physiological host range, we first exposed non-target eggs to mated female A. orientalis wasps in no-choice tests where the wasps had access to the non-target species eggs for a full week of exposure.…”

Cryptic genetic diversity and associated ecological differences of Anastatus orientalis, an egg parasitoid of the spotted lanternfly

“…Intrigued by the contradictory observations of different diapause behaviors exhibited by Anastatus orientalis populations, we aimed to assess mitochondrial diversity within this parasitoid wasp—a potential biological control agent for the invasive spotted lanternfly, Lycorma delicatula —and the association between genetic variability and its life history traits. Our study contributes to the understanding of the biology of A. orientalis , which is critical for wasp rearing and subsequent tests of host specificity ( 34 , 35 ).…”