Do scale insects crawl or jump?

Scale insects exhibit a remarkable pattern of change in their mobility as they progress through their life stages. At the crawler stage, these tiny, pale nymphs are the only life stage with legs that function adequately enough to move. They crawl short distances as they look for a food source. When I have watched them under magnification, they have slowly crawled across a leaf, much slower than ants, which sometimes took several minutes to complete.

Unlike fleas or springtails, scale insects do not leap. They do not have a spring apparatus in their biology. The crawlers move slowly, stopping frequently, and I recorded an average speed of 1 cm per minute. Their main dispersal method is wind to a new host plant.

Female scales cement themselves in a permanent position after completing their settling. During the settling process, female scales insert their mouthparts deep into the plant tissue, creating a strong, fixed connection. Attempting to dislodge the scale from the plant tears its body open, eventually killing it. Immobility is the primary reason scale colonies will grow outward from the point of original infestation.

You can identify mobile crawlers through simple monitoring techniques. I use double-sided tape wrapped around infested branches. The crawlers will adhere to the tape and show movement patterns. I check the tape weekly throughout the growing season. This determines when crawlers are at their peak activity, aiding another targeted control strategy.

The control aspect is related to the mobile crawler stage of the pests. Apply insecticidal soap to the affected weevils once you see active movement on the tape. This vulnerable window lasts only 2-7 days, and if you miss this cycle, it means waiting for the new generation. I often set calendar alerts based on local growing degree days.

Read the full article: Mastering Scale Insect Identification: A Complete Guide