The spotted lanternfly (Lycorma delicatula) is a new exotic pest that was first detected in Pennsylvania in 2014 and has since moved to other nearby states (Figure 1). Everyone, including home gardeners and retail nursery and garden center employees, can play a significant role in keeping this exotic pest out of California by being the eyes and ears needed for early detection.
The spotted lanternfly is a sizable planthopper insect which is about 1 inch long and 0.5 inch wide (Figure 2). It originates from northern China and it can also be found in Vietnam, Japan, and South Korea. This planthopper has a wide host range consisting of more than 70 plant species with at least 40 of the known hosts occurring in North America. This insect causes economic damage to grapevines and also feeds on fruit trees, hops, and woody ornamentals. Its preferred host is the invasive tree of heaven (Ailanthus altissma). Spotted lanternflies have piercing-sucking mouthparts and produce a copious amount of honeydew that enables the growth of sooty molds. In addition to being an agricultural and horticultural pest, the spotted lanternfly can also be a nuisance pest in urban areas due to their aggregation behavior (Figure 3).
Figure 3. Aggregation of adult spotted lanternflies.
Each female produces one to two egg masses of 30 to 50 eggs each. Seedlike eggs are laid in multiple successive rows and covered with a yellowish-brown waxy deposit (Figure 4). The first three immature stages are black with white spots and lack wings. The fourth immature stage is red and black with white spots and have small wing pads (Figure 5).
Adults have a stout yellow abdomen with incomplete black bands and two sets of wings: the forewings and the hindwings. The forewings are a beige-cream color with black spots changing to small black rectangles toward the tips. The hindwings are primarily black and red, with black spots appearing in the red portions. The hindwings are not noticeable when at rest (Figure 6). Adults tend to hop when moving instead of flying.
The spotted lanternfly can negatively affect high value commodity crops in California if it were to become established. In a proactive response to this possibility, researchers at UC Berkeley and UC Riverside are testing biological control agents for this insect.
Since the tree of heaven is the preferred host of the adult spotted lanternfly, these trees can be monitored for presence of the insect. If you suspect you have found this insect, report your sighting to your local county Agricultural Commissioner's office right away. Document the exact location of the finding. Collect the insect in a sealable container you can deliver to the office or take clear photographs of the suspected spotted lanternfly. Nymphs cannot fly and adults do not readily fly away when approached so you can easily collect both. Early detection is key and together, we can all play a role in keeping the spotted lanternfly from establishing in California.
Figure 6. The fourth immature stage and adults of the spotted lanternfly.
[Original article published in the Summer 2020 issue of the Retail Newsletter]